Year	years
1960	47.679
1961	48.374
1962	49.087
1963	49.714
1964	50.434
1965	51.039
1966	51.439
1967	52.035
1968	52.601
1969	53.117
1970	53.63
1971	54.237
1972	54.781
1973	55.374
1974	55.893
1975	56.547
1976	57.015
1977	57.553
1978	58.085
1979	58.439
1980	56.775
1981	57.123
1982	57.644
1983	57.969
1984	58.512
1985	59.041
1986	59.555
1987	60.207
1988	60.248
1989	62.642
1990	62.496
1991	62.098
1992	61.545
1993	60.86
1994	59.846
1995	58.634
1996	56.918
1997	55.558
1998	54.101
1999	53.036
2000	51.99
2001	51.26
2002	51.254
2003	51.083
2004	51.246
2005	51.787
2006	52.655
2007	53.68
2008	54.653
2009	55.496
2010	56.015
2011	56.553
2012	57.64
2013	58.694
2014	59.822
2015	60.7
2016	61.682
2017	62.293
2018	62.586
2019	63.075
2020	62.829
2021	59.269
2022	58.059